6_25 Class notes

Group Activity #1

Your company picnic was this past Saturday afternoon and a good time was had by all. Unfortunately, later Sat night several employees were feeling ill, with symptoms of nausea, vomiting, and diarrhea.

You are charged with determining how they got sick.

You consider: Symptoms, timing of symptoms, handling

Stephylococeus Aureus

Samonella  4 hrs – 2 days (vomiting)

Menu: Sweet Tea, grilled chicken, potato salad (mayniose, eggs), watermelon

We believe the pathogen is Samonella because the incubation period is 4 hours to 2 days and the source would be the uncooked or undercook chicken that may have been improperly handled. The symptoms and timing align: less than one day, nausea, vomiting and diarrhea.

Kristen Bazemore

Harsimran Ahluwalia (Simran)

Which food was the cause?

Potato salad (Staphylococcus)

Clues: timing short, no fever seen

Cause: handled AFTER ingredients cooked, moist, no gloves worn (or preparer sneezed)

*food allowed to sit out at warm temperature…. 2 ½ hours starts when eggs cooked

* Grilled chicken: Salmonella, cross contamination (fever and longer incubation period)

* Sweet tea: E. coli, Hepatitis A, preparer not washing hands after using restroom

* Watermelon: E. Coli, Cholera, Salmonella, Hepatitis A, runoff from nearby farm (wash the outside of the melon)

Robert Hooke: British scientist mid 1600, looked at cork, published book “micrographic”

He did not see any bacteria, called them cells and got people interested in microscopy

Anton van Leeuwenhoek (1632-1723) Fig 1.1 (has microscope in hand, very little) not scientist, rich merchant, import/export. Thread count on sheets, fabric, made own magnifying lens. 300 x 2 plates of brass.

Hooke helped publish drawings (Royal Society of London, only scientific publication 1673-1723) of Leeuwenhoek…. Late 1600 until death early 1700s

·         Viewed pond water, feces, tooth scrapings, semen, etc.

·         First person to see and described:

o   Bacteria- all three basic shapes  (example picture and movement of bacteria)

o   Protozoa

o   Sperm and semen (drawing of sperm he saw with immature baby, humocoulos?)

o   Red blood cells

o   Capillaries

o   Didn’t connect to diseases

o   His microscope was better than everyone else’s but others couldn’t see them

·         No further microscopy discoveries after his death (1723) for over 100 years!

o   Why? Secretive, scope technology lagged

o   Never took an apprentice and did not let Czar or Queen to touch it

o   No one thought it was important

o   “Animacules” not significant in disease or food spoilage

·         Meanwhile, Controversy Sparked debate and experimentation

o   Spontaneous generation

o   Theories of disease

Spontaneous generation: living creatures arise from nonliving components:

Example: eels from mud, maggots from rotting foods, fleas from sweaty cloth

Theories of Disease:

                Hypothesis: Curses by witches

·         Inheritance (they thought tubercolus was)

·         Punishment for sins (example AIDS virus)

·         Miasma- gases of fumes rising from diseased or dead individuals

·         Germs (later)

Miasma: plague cart, plague pole, distance of pole? 10 foot “I wouldn’t touch that with a 10 foot pole” refers to the plague pole. Distance that a “miasma” can spread.

Settling the Disputes: Spontaneous generation: Redi, Pasteur

Causes of disease: Jenner, Semmelweiss, Lister, Pasteur, Koch

Redi’s Meat/Maggot experiments:

·         Developed first CONTROLLED experiment (fig 1. 10) (no maggots)

o   “covered jar” experiment (1670s)

·         Opened jar with meat (maggots on meat)

·         Meshed covered jar with meat (maggots on mesh)

·         Was able to replicate. Results refuted spontaneous generation for MACROorganisms

Dr. Edward Jenner           

·         Worried about people getting sick and dying. Several children

·         Small pox 1796: 2 out of 5 would die of small pox

·         Children who survived would be disfigured: leave craters

·         Cowpox gave people lots of immunity for small pox

·         Milk maids get cowpox, kind of like chicken pox, they did not get small pox

·         Interesting and (illegal) variolation in orient induced “mild” smallpox: put the pus from the legions and put in cut of another person. Cut slit and drag it into another.  They might have a STRONG life threating version but have a strong immune system.

·         Used pus from cowpox to create immunity from smallpox: first vaccination (1796)

o   Then he gave his children smallpox to see if they were immune. Vacca is Latin for cow.

·         They share proteins in the outer coat and your body recognized it as the same thing. Only disease that works: cowpox/smallpox it doesn’t work for any other disease

·         Picture of him doing it for his own child

Semmelweiss- asepsis (1847)

·         Hungarian doctor observed: had a bad attitude doctor? Maternity ward?

o   High “childbirth fever” deaths with doctors

o   Doctors- from cadavers to patients without disinfecting hands or instruments

o   Women would have babies in the alleys to get into midwife ward instead of doctors section

o   Introduced use of lime water for disinfection

o   Mortality rates decreased

o   He said materials but did not know about bacteria or viruses

o   When they didn’t adopt it fast enough, he became accusational: they were killing their patients if they didn’t adopt it: died of blood poisoning in mental institution. Not widely accepted because of how he presented it.

Lister – Aseptic Surgery (1850s)

·         Anesthesia increased mortality rates!

·         Expanded methods of Semmelweiss (less confrontational)

·         Introduced asepsis. (sepsis means spread: techniques not to spread bacteria, etc)

o   Heat sterilization of instruments

o   Disinfection of wounds and dressings

o   Disinfection of air during surgery (airborne particles can cause infection)

·         Did not mention germs but lived overlapping Pasteur

·         Father of Aseptic Surgery

·         Picture: circa 1870 surgery using the Lister techniques

·         Modern picture of surgery

Pasteur and Koch: the golden age of microbiology in 40 years will continue tomorrow.

Topic 1: Welcome to Microbiology!

...Where we boldly go into the realm of those smelly, dangerous, helpful, flavor-enhancing creatures called microorganisms.

What is expected of you in this course:

• I provide:
• Interesting, relevant material for your future careers
• Lecture outlines
• Tools for “getting” difficult material
• review sheets
• organizational charts
• old tests
• lab images
• web resources
• Tests on what was covered in class
• Quick and fair grading
• You agree to:
• Attend each lecture
• Skim assigned material before class, and re-read after covering topics in class
• Be respectful of me and your peers by refraining from talking
• Turn cell phones off or silent!
• Take advantage of resources provided
• Come on time for tests

Read “Microbiology Ground Rules” and initial top of page 4 if you accept the expectations of the course

• Please put the following information on syllabus page 4
• Your name (what you want me to call you also)
• Home phone number for semester (area code, too, if different  from 336) and email address (if active)
• Your major and/or career aspirations
• All college science courses (include chemistry, physics, and biology; but NOT social sciences or nursing)
• Anything else you think I need to know about you (medical, travel, kids, learning disabilities, etc.)

Microbiology is about:

(Fig. 4.3)

• 30%: bacteria
• How  prokaryotic cells work
• clinically significant organisms (Staph, Strep, E.coli, anthrax, etc.)
• antibiotic mechanisms
• antibiotic resistance

• 30% : viruses
• How viruses work
• Clinically significant viruses

–        Influenza, Smallpox, Herpes (1-8), Hepatitis (A-E), AIDS

• Antiviral drug mechanisms
• 10%: Miscellaneous microbes
• Prions
• Protozoa
• Fungi
• 20%: Disease and immunity
• Disease establishment
• Epidemiology
• Immune response

• 10%: Food Microbiology
• Food production
• Food spoilage
• Reducing risks

The History of Microbiology:

The Humble Beginnings:  Microscopy and Controversy

Microscopy

• Robert Hooke: 

§  Anton van Leeuwenhoek (Fig. 1.2, 1.3)

Leeuwenhoek looked at:

Leeuwenhoek was first to describe:

Topic 2: The History of Microbiology:

The Humble Beginnings:

Microscopy and Controversy

Microscopy

Robert Hooke: (1665)

• Contributions to microbiology:

• "Micrographie"

 
 

Anton van Leeuwenhoek (1673-1723)   Fig. 1.1, 1.2

• Royal Society of London

 
 
 
 
 
 

Leeuwenhoek looked at:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Leeuwenhoek was first to describe:
 
 
 
 
 
 
 
 
 
 
 
 
Why did further discoveries languish for nearly 100 years?
 
 
 
 
 
 
Meanwhile, Two Controversies Sparked Debate and Experimentation

• Spontaneous Generation
• Theories of Disease

 
 

Spontaneous Generation:
 
 
 
 
 
 
 
 
 

 
 
Theories of Disease:

• Miasma
   
   
   
   

Settling the Disputes:

Solving the spontaneous generation controversy:

• Redi
• Pasteur

Solving the disease controversy:

• Jenner
• Semmelweiss
• Lister
• Pasteur
• Koch

 
 
 

Redi’s Meat/Maggot Experiments (1670s)

• Famous "covered jar" experiment  Fig. 1.10

 
 
 
 
 
 
 
 
 
 
 
  What controversy did this settle?
 

 
  What method was developed?
 

Jenner’s Smallpox Experiments (1796)

2 observations:

“Variolation”
 
 
 
 
 Developed first:
 
 
 
 

Semmelweiss -Asepsis (1847)
 
 
 
 
 
 
 
 

Lister - Aseptic Surgery (1850’s)